neoplasia flashcards

UCL Cancer Institute

  • Faculty of Medical Sciences

  • Introduction to Neoplasia

  • Dr Sarah Koushyar

    • Email: s.koushyar@ucl.ac.uk

Learning Outcomes

  • By the end of this topic, you should be able to:

    • Define neoplasia.

    • Identify different cancer types.

    • Understand the difference between benign and malignant tumors.

    • Understand basic concepts of cancer biology and carcinogenesis mechanisms.

    • Recognize risk factors for cancer.

    • Understand hallmarks of cancer, which are mechanisms behind cancer pathology.

Neoplasia

  • Definition: Uncontrolled growth of cells or tissues (tumor) capable of invading local healthy tissue.

Cancer

  • Nature of Cancer:

    • A disease characterized by uncontrolled cell growth.

    • Driven by genetic mutations that give cells selective advantages for continued division.

    • Tumors exhibit genetic diversity during development.

Epidemiology of Cancer

  • Global Cancer Observatory (GCO):

    • Provides data about cancer incidence and mortality.

  • Statistics:

    • GLOBOCAN 2022 reported:

      • 19.9 million new cases.

      • 10 million deaths.

      • Mortality: 9.7 million.

Common Cancers

  • Most Common Cancers:

    • Examines the disparity between the most common cancer types and those causing significant mortality.

Classifications of Cancer

  • Types of Cancer:

    • Carcinoma: Cancer of epithelial tissue (e.g., adenocarcinoma).

    • Sarcoma: Cancer of connective tissue (e.g., liposarcoma).

    • Leukemia: Cancer of blood cells/bone marrow.

    • Lymphoma: Cancer of lymphatic tissue.

Cancer Pathology

  • Tumor Development:

    • Process involves years of evolution from normal to neoplastic phenotypes:

      • Stages of dysplasia:

        • Mild → Moderate → Severe Dysplasia

        • Carcinoma in situ → Invasive carcinoma.

  • Colorectal Cancer Progression:

    • Pathologists can identify tumor stage and progression clearly defined in some cancers.

Benign vs Malignant Tumors

  • Characteristics:

    • Benign:

      • Well differentiated, slow growth, normal mitotic figures, non-invasive, and absent metastases.

    • Malignant:

      • Poorly differentiated, fast or slow growth, abnormal mitotic figures, invasive, and often presents metastases.

Causes of Cancer

  • Cancer Potential:

    • Any cell can become cancerous due to intrinsic/extrinsic factors:

      • Extrinsic Factors:

        • Tobacco smoke, UV rays, processed meat, radiation.

      • Intrinsic Factors:

        • Inherited germline mutations, DNA replication errors, free radicals.

Cancer Progression

  • Critical Genes:

    1. Proto-oncogenes: Regulate cell growth (e.g., C-MYC, RAS).

    2. Tumor Suppressors: Prevent tumor development (e.g., P53, PTEN).

    3. Apoptotic Genes: Control apoptosis (e.g., BAX, BCL-2).

    4. DNA Repair Genes: Repair DNA damage (e.g., BRCA1/2).

Tumor Suppressors & Oncogenes

  • Tumor Suppressors:

    • Function to limit cellular proliferation and repair DNA damage.

    • Loss of function is crucial for cancer development.

  • Oncogenes:

    • Mutated proto-oncogenes can drive cancer through increased function; usually, one mutation is enough.

Key Pathways in Cancer

  • Pathways involved in cancer regulate:

    • Cell growth, differentiation, metabolism, stability, migration, and apoptosis.

Metastasis Process

  1. Primary tumor growth.

  2. Stromal invasion.

  3. Intravasation into circulation.

  4. Extravasation into new tissue.

  5. Colonization.

Cancer Treatment Approaches

  • Methods:

    • Chemotherapy, radiotherapy, surgery.

  • Limitations:

    • Toxicity, treatment resistance, challenges targeting metastatic regions.

Personalized Medicine

  • Driver Mutations:

    • Advancements in precision cancer therapy through genetic profiling and stratification can enhance treatment effectiveness.

Upcoming Lectures

  • Topics to include various forms of hemato-oncology and specific cancer types.

Summary

  • Cancer represents uncontrolled cell growth capable of invading tissues and is a leading global cause of death.

  • Understanding of cancer biology, including genetic predispositions, is vital for developing effective treatments.

Recommended Reading

  1. "The Emperor of All Maladies" by Siddhartha Mukherjee.

  2. "The Gene: An Intimate History" by Siddhartha Mukherjee.

  3. "The Unseen Body" by Jonathan Reisman.

  4. "The Beautiful Cure" by Daniel M Davis.

  5. "The Immortal Life of Henrietta Lacks" by Rebecca Skoot.

  6. "The Biology of Cancer" by Robert A. Weinberg.

  7. Podcast: "Cancer Research Matters" - Cancer Research UK.